Physic-chemical conditions of gold-bearing magnetite-chlorite-carbonate roks' formation of the Karabash ultramafic massif (the Southern Urals)

• Main Authors: Valerii V. Murzin, Svetlana N. Shanina
• Format: Article
• Language: English
• Published: A.N. Zavaritsky Institute of Geology and Geochemistry 2017-12-01
• Series: Литосфера
• Subjects: газово-жидкие включения; магнетит-хлорит-карбонатные породы; хлоритолиты; родингиты; самородное золото; fluid inclusions; magnetite-chlorite-carbonate rocks; chloritolites; rodingites; native gold
• Online Access: https://www.lithosphere.ru/jour/article/view/128

In the paper, there are adduced the data of a thermobarogeochemistry investigation of fluid inclusions in apatite of magnetite-chlorite-carbonates rocks from ultrabasite Karabash massife. The rocks are carrying copper-bearing aurum (1.3-2.6 wt % Cu) and was formed at temperature in the range of 480-280°C and a pressure of about 2-3 kbar. The content of the inclusions corresponds to the salt system of H2O-NaCl and the salt concentration in the solution 3.7-8.8 wt % eq. NaCl. Fluids gas components, extraction by pirolysis up to temperature 450°C, are described by a system C-H-O with an insignificantly amount of nitrogen. In fluid composition presents a small amount of the reduced gasses - CO, H2, CH4, hard carbon-hydrates (C2H4, C2H6, C3H6, C3H8 etc.). Adduced comparative analysis of fluid composition and the degree of oxidation fluid gas component (Ofl = CO2/(CO2 + CO + H2 + CH4) during the forming magnetite-chlorite-carbonate rocks, the rodingites and the listwenites. It is established, that carbon acid part of mole in fluid (XCO2) grown from extremely low value by the forming of rodingites with copper-bearing aurum (